CA1189660A - Process for the production of pitch-derived carbon fibers - Google Patents
Process for the production of pitch-derived carbon fibersInfo
- Publication number
- CA1189660A CA1189660A CA000418355A CA418355A CA1189660A CA 1189660 A CA1189660 A CA 1189660A CA 000418355 A CA000418355 A CA 000418355A CA 418355 A CA418355 A CA 418355A CA 1189660 A CA1189660 A CA 1189660A
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- Prior art keywords
- pitch
- oil
- heavy fraction
- temperature
- petroleum
- Prior art date
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10C—WORKING-UP PITCH, ASPHALT, BITUMEN, TAR; PYROLIGNEOUS ACID
- C10C3/00—Working-up pitch, asphalt, bitumen
- C10C3/002—Working-up pitch, asphalt, bitumen by thermal means
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
- D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
- D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof
- D01F9/14—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments
- D01F9/145—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from pitch or distillation residues
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Thermal Sciences (AREA)
- Civil Engineering (AREA)
- Physics & Mathematics (AREA)
- Structural Engineering (AREA)
- Materials Engineering (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Chemistry (AREA)
- Textile Engineering (AREA)
- Inorganic Fibers (AREA)
- Working-Up Tar And Pitch (AREA)
Abstract
PROCESS FOR THE PRODUCTION OF
PITCH-DERIVED CARBON FIBERS
Abstract of the disclosure:
A process for the production of high performance carbon fibers which comprises using as the starting material a specific pitch having the lowest reflectivity in the range of 8.5-9.3% and the highest reflectivity in the range of 11.8-12.5%.
PITCH-DERIVED CARBON FIBERS
Abstract of the disclosure:
A process for the production of high performance carbon fibers which comprises using as the starting material a specific pitch having the lowest reflectivity in the range of 8.5-9.3% and the highest reflectivity in the range of 11.8-12.5%.
Description
i6~
This invention relates to an excellent specific pitch for producing high performance carbon fibers.
There have recently been reported many methods for producing carbon fibers from pitch. It is said that, in the case of production of carbon fibers from pitch, the tensile modulus, tensile strength and the like of the resulting carbon iibers depend greatly upon the properties of the pitch. For example, Japanese Patent Gaæette 55-37611 describes that the use of a pitch con-taining 40-90% of mesophase portions is essential in the production of high performance carbon fibers. However, it is necessary to heat treat pitch at a temperature of at least 350C for usually 10 hours in order to obtain a pitch containing 40-90~ of mesophase. In addition, since such a mesophase-containing pitch has a softening point of usually at least 300C, the melt spinning thereof must be effected at a high temperature of at least 350C. The higher softening point a pitch has, the higher the temperature needed for melt spinning the pitch is; this is not only economically disadvantageous but also tends to cause thermal degradation, such as an increase in quinoline-insoluble ingredients and evolution of decomposition gases, in the pitch in the melt spinlli.ng step thereby rendering it diffic~llt to obtain high per~ormance carbon fibers.
An object of this invention is to provide a specific reformed pitch which may be prepared in a comparatively short time 9 has a low softening point and is excellent for use as material for producing high performance carbon fibers. Thus, the specific pitch according to this invention will produce high performance carbon fibers therefrom, The process o this invention comprises producing high performance carbon fibers from a specific pitch having the lowest reflectivity in the range of 8.5-9.3% and the highes~ reflectivity in the range of 11.8-12~5%.
The reflectivity is de-termined by embedding a test pitch in a resin such as an acryl resin, grinding the pitch-embedded resin until the pitch surface appears outside and then measuring the pitch surface reflectivity in air b~ an apparatus for measurement of reflectivity, More particularly, at least 100 sites are op-tionally selected on the pitch surface, the pitch surface is rotated 360C
around each of the sites as the rotation center to measure the maximum and minimum reflectivities at each site. The highest value of the maximum reflectivities measured and the lowest value of the minimum reflect.ivities measured are taken as the highest and lowest reflectivities for the test pitch.
It is only a specific pitch having the thus measured lowest value in the range of 8.5-9.3% and the thus measured highest value in the range o:E ~1.3-12.5% that is most suitable as pitch or producing high per:Eormance carbon fibers therefrom. A pitch having at least one of its highest and lowest reflectivities falling outside the ~5 corresponding specified reflectivity ranges, has no longer excellent properties necessary for a pitch for carbon fibers whereby it cannot produce high performance carbon fibers therefrom, The method for preparing a specific pi~ch having the specified reflectivities according to this invention 66~
as well as a starting pitch for preparing the specific pitch therefrom, is not particularly limited.
The starting pitches used herein are carbonaceous pitches such as a coal-derived pitch and petroleum derived pitch, among which is preferred a pitch containing no mesophase portions and having a softening point of 50-200C.
The starting carbonaceous pitches suitable for producing the specific pitches are illustrated by:
~ 1) a heavy fraction oil boiling at substantially 200-450C obtained as a by-product at the time of steam cracking of petroleum, such as naphtha, kerosene or light oil, at usually 700-1200C to produce olefins such as ethylene and propylene,
This invention relates to an excellent specific pitch for producing high performance carbon fibers.
There have recently been reported many methods for producing carbon fibers from pitch. It is said that, in the case of production of carbon fibers from pitch, the tensile modulus, tensile strength and the like of the resulting carbon iibers depend greatly upon the properties of the pitch. For example, Japanese Patent Gaæette 55-37611 describes that the use of a pitch con-taining 40-90% of mesophase portions is essential in the production of high performance carbon fibers. However, it is necessary to heat treat pitch at a temperature of at least 350C for usually 10 hours in order to obtain a pitch containing 40-90~ of mesophase. In addition, since such a mesophase-containing pitch has a softening point of usually at least 300C, the melt spinning thereof must be effected at a high temperature of at least 350C. The higher softening point a pitch has, the higher the temperature needed for melt spinning the pitch is; this is not only economically disadvantageous but also tends to cause thermal degradation, such as an increase in quinoline-insoluble ingredients and evolution of decomposition gases, in the pitch in the melt spinlli.ng step thereby rendering it diffic~llt to obtain high per~ormance carbon fibers.
An object of this invention is to provide a specific reformed pitch which may be prepared in a comparatively short time 9 has a low softening point and is excellent for use as material for producing high performance carbon fibers. Thus, the specific pitch according to this invention will produce high performance carbon fibers therefrom, The process o this invention comprises producing high performance carbon fibers from a specific pitch having the lowest reflectivity in the range of 8.5-9.3% and the highes~ reflectivity in the range of 11.8-12~5%.
The reflectivity is de-termined by embedding a test pitch in a resin such as an acryl resin, grinding the pitch-embedded resin until the pitch surface appears outside and then measuring the pitch surface reflectivity in air b~ an apparatus for measurement of reflectivity, More particularly, at least 100 sites are op-tionally selected on the pitch surface, the pitch surface is rotated 360C
around each of the sites as the rotation center to measure the maximum and minimum reflectivities at each site. The highest value of the maximum reflectivities measured and the lowest value of the minimum reflect.ivities measured are taken as the highest and lowest reflectivities for the test pitch.
It is only a specific pitch having the thus measured lowest value in the range of 8.5-9.3% and the thus measured highest value in the range o:E ~1.3-12.5% that is most suitable as pitch or producing high per:Eormance carbon fibers therefrom. A pitch having at least one of its highest and lowest reflectivities falling outside the ~5 corresponding specified reflectivity ranges, has no longer excellent properties necessary for a pitch for carbon fibers whereby it cannot produce high performance carbon fibers therefrom, The method for preparing a specific pi~ch having the specified reflectivities according to this invention 66~
as well as a starting pitch for preparing the specific pitch therefrom, is not particularly limited.
The starting pitches used herein are carbonaceous pitches such as a coal-derived pitch and petroleum derived pitch, among which is preferred a pitch containing no mesophase portions and having a softening point of 50-200C.
The starting carbonaceous pitches suitable for producing the specific pitches are illustrated by:
~ 1) a heavy fraction oil boiling at substantially 200-450C obtained as a by-product at the time of steam cracking of petroleum, such as naphtha, kerosene or light oil, at usually 700-1200C to produce olefins such as ethylene and propylene,
(2) a heavy fraction oil boiling at substantially 200-450C obtained as a by-product at the time of fluidized catalytic crac~ing of petroleum such as kerosene, light oil or atmospheric pressure bottom oils at a temperature of 450 550C and a pressure of atmospheric to 20 Kg/cm2oG
in the presence of natural or synthetic silica~alumina catalyst or zeolite catalyst,
in the presence of natural or synthetic silica~alumina catalyst or zeolite catalyst,
(3) a pi.tch obtained by incorporating 100 parts by volume of said heavy fraction oil (1) with 10-200 parts by volume of aromatic hydrocarbons of 2-3 rings having their nuclei at least partly hydrogenated to form a mixed oil and then heat treating the thus formed mixed oil at a temperature of 370-480C and a pressure o~ 2-50 Kg/cm G,
(4) a pitch obtained by incorporating 100 parts by volume of said heavy fraction oil (2) with 10-200 parts by volume of aromatic hydrocarbons of 2 3 rings having their nuclei at least partly hydrogenated to form a mixture and ~ 4 -then heat treating the thus formed mixture at a temperature of 370-480C and a pressure oE 2-50 Kg/cm2-G,
(5) a pitch obtained by heat treating said heavy fraction (1) at a temperature of 400-500C under a hydrogen pressure of 20 350 Kg/cm2~G,
(6) a pitch obtained by heat trea-ting said heavy fraction oil (2) at a temperature of 400-500C under a hydrogen pressure of 20-3S0 Kg/cm2~G,
(7) a pitch obtained by (A) incorporating 100 parts by volume of said heavy fraction oil (1) with 10-200 parts by volume of a hydrogenated oil (2) ob-tained by contacting with hydrogen in ~he presence of a hydrogenating catalyst a fraction (i) boiLing at 160-400C produced at the time of steam cracking of petroleum and/or a fraction (ii) boiling between 160-400C produced at the time of heat treating at 370-480C a heavy fraction oil boiling at not lower than 200C obtained at the time of steam cracking of petroleum, to hydrogenate 10-70% of aromatic nuclei oE
the aromatic hydrocarbons contained in the fractions (:L) 20 and (ii) thereby to obtain a mixture of the oils ~1) and (2) and then (B) heat treating the thus obtained mixture at a temperature of 370-480C under a pressure of 2~50 ~g/cm ~G thereby obtaining the pitch~ and
the aromatic hydrocarbons contained in the fractions (:L) 20 and (ii) thereby to obtain a mixture of the oils ~1) and (2) and then (B) heat treating the thus obtained mixture at a temperature of 370-480C under a pressure of 2~50 ~g/cm ~G thereby obtaining the pitch~ and
(8) a pitch obtained by mixing together the heavy 25 fraction oil (1), heavy fraction oil (2) and hydrogenated oil (7) in such amounts that the ratio by weight of said heavy fraction oil (1) to said heavy fraction oil (2) is 1:0.1-9 and the ratio by weight of the total of said heavy fraction oils (1~ and (2) to said hydrogenated oil (7) is 30 1:0.1-2, to obtain a mixture and then heat treating the thus obtained mixture at a temperature of 370~480C under a pressure of 2-50 Kg/cm2~G thereby obtaining the pitch.
~nong the abovementioned starting pitches for producing the specific pitch according to this invention, the pitches (2), (~), (6~, (7) and (~) are preferred.
The nucleus-hydrogenated aromatic hydrocarbons of 2-3 rings used in the preparation of the pitches (3) and (~) include naphthalene, indene, biphenyl, acenaphthylene, anthracene, phenanthren and their C1 3 alkyl-substituted compoundsl in each of which 10 100%, preferably 10-70~ of the aromatic nuclei have been hydrogenated. More specifically, they include decalin, methyldecalin, tetralin, methyltetralin, dimethyltetralin, ethyltetralin, isopropyltetralin, indane, decahydrobiphenyl, acenaphthene, methylacenaphthene, -tetrahydroacenaphthene, dihydroanthracene, methylhydroanthracene~ dimethylhydro-anthracene, ethylhydroanthracene, tetrahydroanthracene, hexahydroanthracene, octahydroanthracene, dodecahydro anthracene, tetradecahydroanthracene, dihydrophenanthrene, methyldihydrophenanthrene, tetrahydrophenanthrene, hexahydrophenanthrene, octahydrophenanthrene, dodecahydro-phenanthrene and tetradecahydrophenanthrene They rnay be used alone or in combination. Particularly preferred are nucleus-hydrogenated aromatic hydrocarbons obtained from bicyclic or tricyclic condensed aromatic hydrocarbons.
The methods for producing the specific pitches according to this invention are not specifically limited.
These specific pitches may be obtained, for example, by a method comprising melting the starting material for the specific pitches to make it liquid in an inert gas ~9~
atmosphere, forming the melted liquid material into a filmy shape having a thickness of preferably up to 5 mm, heat treating the thus obtained Eilms at 200-350C, preferably 250-345C, and a reduced pressure, preferably 001-10 mmHg, for 1-30 minutes, preferabLy 5-20 minutes and then further heat treating the thus heat treated films at 300-450C, preferably 350-400C, for 1-60 minutes~ preferably 5-40 minutes. By the use of such treatments, the starting material may be converted to a desired specific pi-tch having the lowest reflectivity in the range of 8.5-9.3~ and the highest reflectivity in the range of 11.8-12.5%.
The specific pitches having the specified reflectivities according to this invention are melt spun by a usual method to obtain pitch Eibers, infusibilized, carbonized or further graphitized to obtain carbon Eibers having high tensile modulus and high tensiLe strength.
The melt spinning may be effected usually by adjusting the melt spinning temperature to a temperature approximately 40-70C higher than the softening point of the specific pitch and ex-truding the thus melted pitch through nozzles having a diameter of 0.1-0.5 mm so that the resulting carbon fibers are taken up at a velocity of 200-2000 m/min. on take~up rolls.
The pitch fibers obtained by melt spinning the starting pitch are then infusibilized in an oxidizing gas atmosphere (20-100% concentration). The oxidizing gases which may usually be used herein, include oxygen, ozone t air r nitrogen oxides, halogen and sulfuxous acid gas. These oxidizing gases may be used singly or in combination The infusibilizing treatment may be effected at such a ~ 7 --temperature that the pitch fibers obtained by melt spinning are neither softened nor deformed; thus, the infusibilizing temperature may be, for example, 20-360C, preferably 20-300C. The time for the infusibilization may usually be in the range of S minutes to 10 hours.
The pitch fibers so infusibilized are then carbonized or further graphi-tized to obtain carbon fibers, The carbonization or graphitization is effected by heating the infusibilized pitch fibers at a heat-raising rate of 5-20C/min. to 800-3500C and maintaining them at this temperature for one second to one hourO
Example 1 There was obtained a heavy fraction oil (A) boiling at not lower than 200C produced as a by-product at the time of fluidized catalytic cracking at 500C of light oil in the presence of zeolite ca-talyst, The characteristics of the thus obtained oil (E) are as shown in Table 1.
~ 8 Table 1 Distillation Characteristics of Heavy Fraction Oil (A) Specific gravity (15C/4C) 00965 Initial boiling point 320 (C) 5 (%) 340 2~ 370 Distillation 30 385 characteristics 4~5 one hundred and fifty (150) ml of the thus obtained heavy fraction oil (A) were introduced into a 300-ml autoclave provided with an agitator, heated at 3C/min. to 430C under an initial hydrogen pressure of 100 Kg/cm ~G and maintained at this temperature for 3 hours~
a:Eter which the heating was stoppecl and the reaction produc-t cooled to room temperature. The resulting li~uid product was dlstilled at 250C/1 mmHg to distil off the light fraction thereby obtaining a pitch (1). ~he -thus obtained starting pitch (1) had a softening point of 68C.
The starting pitch (1) was treated at a ~emperature of 345C and a reduced pressure of 1 mmHg for 15 minutes by the use of a ilm evaporator and ~hen heat treated at 350C at atmospheri.c pressure for 15 minutes to obtain a specific pitch (2) having a softening point _ g ~ ~ ~6~
cf softening point of 245C. The thus obtained specific pitch (2) was measured for reflectivity by the use of a reElectivity measuring apparatus produced by Leiz Company (Ernst Leitz G~m~b,H,) with the result that the highest value was 12.0~ and the lowest value was 8,8~, The specific pitch (2) so obtained was melt spun at a spinning temper-ature of 310C and a take-up velocity of 800 m/min. by the use of a spinner having 0,3 mm-diameter nozzles and L/D-1 to obtain 12~-diameter pitch fibers which were infusibi-10 lized, carbonized and graphitized under the following conditions to obtain carbon fibers, Infusibilizing conditions: Raised at 1~C/min, to 300C and maintained at this temperature for 30 minutes in air.
Carbonizing conditions: Raised at 10C~min, to 1000C and maintained at this temperature for 30 minutes in a nitrogen atmosphere.
Graphitizing conditions: Raised at 50C/min. to 2000C and maintained at this temperature for one minute in an argon stream for heat treatment, The carbon fibers so obtained had a 11-~ diameter, a ~ensile strength of 230 Kg/mm2 and a tensile modulus of 25 ton/mm2, Comparative Example 1 The starting pitch (1) as obtained in Example 1 was heat treated at 400C for 6 hours while being agitated by passing nitrogen to the pitch at a flow rate of 2 ml~min.
per gram of the pitch (1) to obtain a pitch (3) having a softening point of 263C. The thus obtained pitch (3) was 30 measured for reflectivi-ty with the result that the highest 3$~
and lowest values were 12.4% and ~,4% respectively.
The pitch (3) was attempted to be melt spun at a spinning temperature of 320C and a take-up velocity of 800 m/min. by the use of the same spinner as used in Example 1, however/ it wa~ impossible to melt spin the pitch uniformly.
Example 2 There was recovered a heavy fraction oil (B) produced as a by~product at the time of steam cracking naphtha at 830C. The characteristics of the heavy fraction oil (B) are as shown in Table 2. The oil (B) was hea^t treated at 400C and 15 Kg/cm2-G for 3 hours to obtain a heat treated oil (C). The thus obtained oil (C) was distilled at 250C/1.0 mmHg -to obtain a fraction (D) boiling at 160-400C. The characteristics of the fraction (D) are as shown in Table 3. The fraction (D) was contacted with hydrogen at 330C, 35 Kg/cm ~G and a LHSV of 1.5 to effect partial nuclear hydrogenation thereby obtaining a hydrogenated oil (E). The degree of nuclear hydrogenation was 31~.
Fifty (50) parts by volume of the heavy fraction oil (B) were mixed with 50 parts b~ volume of the hydrogenated oil (E) to form a mixture which was heat ~reated at 430C and 20 Kg/cm2-G for 3 hours to obtain a heat treated oil. The thus obtained heat treated oil was distilled at 250C/1.0 mmHg to distil off the light fraction thereby obtaining a starting pitch (4) having a softening point of 100C.
The thus obtained starting pitch (4) was heat treated at 345C at a reduced pressure of 1 mn~lg for 15 minutes by the use oE a film evaporator and then Xurther hea~ treated at 380C under atmospheric pressure for 30 minutes to obtain a specific pi~ch (5) having a softening point of 232C. The pitch (5) so obtained was measured for reflectivity with the result that the highest and lowest values were 12.3% and 9.1% respectively, This pitch (5) was melt spun at a spinning temperature of 315C and a take-up velocity of 800 m/min.
by the use of the same spinner as used in Example 1 to obtain 13~-diameter pitch fibers which were infusibilized, carbonized and graphitized to obtain carbon fibers havi.ng an 11-~ diameter~ a tensile strength of 220 Kg/mm2 and a tensile modulus of 24 Ton/mm2.
TabLe 2 Distillation Characteristics of Heavy Fracti.on Oil (B) .
Specific gravity (1SC/4C) 1.03~
Ini~ial boiling point 1g2 ~C) 5 (%) 200 Distillation 30 227 characteristics ~1 3~0 Table 3 Distillation Characteristics of Fraction (D) Specific gravity (15C/4C) 0.991 Refractive index ~n2D5) 1.5965 Molecular weight 145 Initial boiling point 160 (C) 10 (%) 200 Distillation 30 215 characteristics 50 230 Comparative Example 2 The pitch (4) as obtained in Example 2 was heat treated at 400C for 12 hours while being agitated by passing nitrogen at a flow rate of 2 ml/min, per gram of the pitch (4) to obtain a pitch (6) having a 50Etening point of 301C. The thus obtained pitch (6) was measured for reflectivity with the result that the highest and lowest values were l3.3% and 9.1~ respectively.
The pitch (6) was attempted to be melt spun at a spinning temperature of 355C and a take-up velocity of 800 m/min. by the use of the spinner as used in Example 1 with the result that the pitch (6) was thermally degraded whereby continuous spinning was impossibleO
Example 3 Sixty (60) parts by weight of the heavy fraction oil (A) as obtained in Example 1, 30 parts by weight of the heavy fraction oil (B) as obtained in Example 2 and 10 parts by weight of the hydrogenated oil (E) as obtained in Example 2, were mixed together to form a mixed oil which was then heat treated at 430C and 20 Kg/cm2oG for 3 hours to obtain a heat treated oil, The thus obtained heat treated oil was distilled at 250C/1.0 mmHg to distiL off the light fraction thereby obtaining a starting pitch (7) having a softening point 80C.
The starting pitch (7) so obtained was treated at 34$C and a reduced pressure of 1 mm~lg for 15 minutes by the use of a film evaporator and then heat treated at 370C at atmospheric pressure for 20 minutes to obtain a specific pitch (8) having a softening point of 261C. The thus obtained pitch (8) was measured for reflectivity with the result that the highest and lowest values are 12.4%
and 9.0% respectiveLy.
The pitch (8) was melt spun at a spinning temperature of 320C and a take-up speed of 780 m/min. to obtain 12~-diameter pitch fibers. The thus obtained pitch ~ibers were infusibilized~ carbonized and graphitized under the same conditions as in Example 1 to obtain carbon fibers havirlg a 10-~ diameter, a tensile strength oE 220 Ky/mm2 and a tensile modulus of 23 Ton~mm2.
Compara-tive Example 3 The pitch (7) as obtained in Example 3 was heat treated at 400C and a reduced pressure of 1 mm~lg for 10 hours to obtain a pitch (9) having a softening point of 299C and a reflectivity of 13.2% at the highest and 9.0 at the lowest.
The thus obtained pitch (9) was attempted to be ~ 14 -~ 3 melt spun at a spinning temperature of 360C and a -take-up velocity of 780 m/min. with the result that the pitch (93 was thermally degraded whereby continuous spinning thereof was impossible.
~nong the abovementioned starting pitches for producing the specific pitch according to this invention, the pitches (2), (~), (6~, (7) and (~) are preferred.
The nucleus-hydrogenated aromatic hydrocarbons of 2-3 rings used in the preparation of the pitches (3) and (~) include naphthalene, indene, biphenyl, acenaphthylene, anthracene, phenanthren and their C1 3 alkyl-substituted compoundsl in each of which 10 100%, preferably 10-70~ of the aromatic nuclei have been hydrogenated. More specifically, they include decalin, methyldecalin, tetralin, methyltetralin, dimethyltetralin, ethyltetralin, isopropyltetralin, indane, decahydrobiphenyl, acenaphthene, methylacenaphthene, -tetrahydroacenaphthene, dihydroanthracene, methylhydroanthracene~ dimethylhydro-anthracene, ethylhydroanthracene, tetrahydroanthracene, hexahydroanthracene, octahydroanthracene, dodecahydro anthracene, tetradecahydroanthracene, dihydrophenanthrene, methyldihydrophenanthrene, tetrahydrophenanthrene, hexahydrophenanthrene, octahydrophenanthrene, dodecahydro-phenanthrene and tetradecahydrophenanthrene They rnay be used alone or in combination. Particularly preferred are nucleus-hydrogenated aromatic hydrocarbons obtained from bicyclic or tricyclic condensed aromatic hydrocarbons.
The methods for producing the specific pitches according to this invention are not specifically limited.
These specific pitches may be obtained, for example, by a method comprising melting the starting material for the specific pitches to make it liquid in an inert gas ~9~
atmosphere, forming the melted liquid material into a filmy shape having a thickness of preferably up to 5 mm, heat treating the thus obtained Eilms at 200-350C, preferably 250-345C, and a reduced pressure, preferably 001-10 mmHg, for 1-30 minutes, preferabLy 5-20 minutes and then further heat treating the thus heat treated films at 300-450C, preferably 350-400C, for 1-60 minutes~ preferably 5-40 minutes. By the use of such treatments, the starting material may be converted to a desired specific pi-tch having the lowest reflectivity in the range of 8.5-9.3~ and the highest reflectivity in the range of 11.8-12.5%.
The specific pitches having the specified reflectivities according to this invention are melt spun by a usual method to obtain pitch Eibers, infusibilized, carbonized or further graphitized to obtain carbon Eibers having high tensile modulus and high tensiLe strength.
The melt spinning may be effected usually by adjusting the melt spinning temperature to a temperature approximately 40-70C higher than the softening point of the specific pitch and ex-truding the thus melted pitch through nozzles having a diameter of 0.1-0.5 mm so that the resulting carbon fibers are taken up at a velocity of 200-2000 m/min. on take~up rolls.
The pitch fibers obtained by melt spinning the starting pitch are then infusibilized in an oxidizing gas atmosphere (20-100% concentration). The oxidizing gases which may usually be used herein, include oxygen, ozone t air r nitrogen oxides, halogen and sulfuxous acid gas. These oxidizing gases may be used singly or in combination The infusibilizing treatment may be effected at such a ~ 7 --temperature that the pitch fibers obtained by melt spinning are neither softened nor deformed; thus, the infusibilizing temperature may be, for example, 20-360C, preferably 20-300C. The time for the infusibilization may usually be in the range of S minutes to 10 hours.
The pitch fibers so infusibilized are then carbonized or further graphi-tized to obtain carbon fibers, The carbonization or graphitization is effected by heating the infusibilized pitch fibers at a heat-raising rate of 5-20C/min. to 800-3500C and maintaining them at this temperature for one second to one hourO
Example 1 There was obtained a heavy fraction oil (A) boiling at not lower than 200C produced as a by-product at the time of fluidized catalytic cracking at 500C of light oil in the presence of zeolite ca-talyst, The characteristics of the thus obtained oil (E) are as shown in Table 1.
~ 8 Table 1 Distillation Characteristics of Heavy Fraction Oil (A) Specific gravity (15C/4C) 00965 Initial boiling point 320 (C) 5 (%) 340 2~ 370 Distillation 30 385 characteristics 4~5 one hundred and fifty (150) ml of the thus obtained heavy fraction oil (A) were introduced into a 300-ml autoclave provided with an agitator, heated at 3C/min. to 430C under an initial hydrogen pressure of 100 Kg/cm ~G and maintained at this temperature for 3 hours~
a:Eter which the heating was stoppecl and the reaction produc-t cooled to room temperature. The resulting li~uid product was dlstilled at 250C/1 mmHg to distil off the light fraction thereby obtaining a pitch (1). ~he -thus obtained starting pitch (1) had a softening point of 68C.
The starting pitch (1) was treated at a ~emperature of 345C and a reduced pressure of 1 mmHg for 15 minutes by the use of a ilm evaporator and ~hen heat treated at 350C at atmospheri.c pressure for 15 minutes to obtain a specific pitch (2) having a softening point _ g ~ ~ ~6~
cf softening point of 245C. The thus obtained specific pitch (2) was measured for reflectivity by the use of a reElectivity measuring apparatus produced by Leiz Company (Ernst Leitz G~m~b,H,) with the result that the highest value was 12.0~ and the lowest value was 8,8~, The specific pitch (2) so obtained was melt spun at a spinning temper-ature of 310C and a take-up velocity of 800 m/min. by the use of a spinner having 0,3 mm-diameter nozzles and L/D-1 to obtain 12~-diameter pitch fibers which were infusibi-10 lized, carbonized and graphitized under the following conditions to obtain carbon fibers, Infusibilizing conditions: Raised at 1~C/min, to 300C and maintained at this temperature for 30 minutes in air.
Carbonizing conditions: Raised at 10C~min, to 1000C and maintained at this temperature for 30 minutes in a nitrogen atmosphere.
Graphitizing conditions: Raised at 50C/min. to 2000C and maintained at this temperature for one minute in an argon stream for heat treatment, The carbon fibers so obtained had a 11-~ diameter, a ~ensile strength of 230 Kg/mm2 and a tensile modulus of 25 ton/mm2, Comparative Example 1 The starting pitch (1) as obtained in Example 1 was heat treated at 400C for 6 hours while being agitated by passing nitrogen to the pitch at a flow rate of 2 ml~min.
per gram of the pitch (1) to obtain a pitch (3) having a softening point of 263C. The thus obtained pitch (3) was 30 measured for reflectivi-ty with the result that the highest 3$~
and lowest values were 12.4% and ~,4% respectively.
The pitch (3) was attempted to be melt spun at a spinning temperature of 320C and a take-up velocity of 800 m/min. by the use of the same spinner as used in Example 1, however/ it wa~ impossible to melt spin the pitch uniformly.
Example 2 There was recovered a heavy fraction oil (B) produced as a by~product at the time of steam cracking naphtha at 830C. The characteristics of the heavy fraction oil (B) are as shown in Table 2. The oil (B) was hea^t treated at 400C and 15 Kg/cm2-G for 3 hours to obtain a heat treated oil (C). The thus obtained oil (C) was distilled at 250C/1.0 mmHg -to obtain a fraction (D) boiling at 160-400C. The characteristics of the fraction (D) are as shown in Table 3. The fraction (D) was contacted with hydrogen at 330C, 35 Kg/cm ~G and a LHSV of 1.5 to effect partial nuclear hydrogenation thereby obtaining a hydrogenated oil (E). The degree of nuclear hydrogenation was 31~.
Fifty (50) parts by volume of the heavy fraction oil (B) were mixed with 50 parts b~ volume of the hydrogenated oil (E) to form a mixture which was heat ~reated at 430C and 20 Kg/cm2-G for 3 hours to obtain a heat treated oil. The thus obtained heat treated oil was distilled at 250C/1.0 mmHg to distil off the light fraction thereby obtaining a starting pitch (4) having a softening point of 100C.
The thus obtained starting pitch (4) was heat treated at 345C at a reduced pressure of 1 mn~lg for 15 minutes by the use oE a film evaporator and then Xurther hea~ treated at 380C under atmospheric pressure for 30 minutes to obtain a specific pi~ch (5) having a softening point of 232C. The pitch (5) so obtained was measured for reflectivity with the result that the highest and lowest values were 12.3% and 9.1% respectively, This pitch (5) was melt spun at a spinning temperature of 315C and a take-up velocity of 800 m/min.
by the use of the same spinner as used in Example 1 to obtain 13~-diameter pitch fibers which were infusibilized, carbonized and graphitized to obtain carbon fibers havi.ng an 11-~ diameter~ a tensile strength of 220 Kg/mm2 and a tensile modulus of 24 Ton/mm2.
TabLe 2 Distillation Characteristics of Heavy Fracti.on Oil (B) .
Specific gravity (1SC/4C) 1.03~
Ini~ial boiling point 1g2 ~C) 5 (%) 200 Distillation 30 227 characteristics ~1 3~0 Table 3 Distillation Characteristics of Fraction (D) Specific gravity (15C/4C) 0.991 Refractive index ~n2D5) 1.5965 Molecular weight 145 Initial boiling point 160 (C) 10 (%) 200 Distillation 30 215 characteristics 50 230 Comparative Example 2 The pitch (4) as obtained in Example 2 was heat treated at 400C for 12 hours while being agitated by passing nitrogen at a flow rate of 2 ml/min, per gram of the pitch (4) to obtain a pitch (6) having a 50Etening point of 301C. The thus obtained pitch (6) was measured for reflectivity with the result that the highest and lowest values were l3.3% and 9.1~ respectively.
The pitch (6) was attempted to be melt spun at a spinning temperature of 355C and a take-up velocity of 800 m/min. by the use of the spinner as used in Example 1 with the result that the pitch (6) was thermally degraded whereby continuous spinning was impossibleO
Example 3 Sixty (60) parts by weight of the heavy fraction oil (A) as obtained in Example 1, 30 parts by weight of the heavy fraction oil (B) as obtained in Example 2 and 10 parts by weight of the hydrogenated oil (E) as obtained in Example 2, were mixed together to form a mixed oil which was then heat treated at 430C and 20 Kg/cm2oG for 3 hours to obtain a heat treated oil, The thus obtained heat treated oil was distilled at 250C/1.0 mmHg to distiL off the light fraction thereby obtaining a starting pitch (7) having a softening point 80C.
The starting pitch (7) so obtained was treated at 34$C and a reduced pressure of 1 mm~lg for 15 minutes by the use of a film evaporator and then heat treated at 370C at atmospheric pressure for 20 minutes to obtain a specific pitch (8) having a softening point of 261C. The thus obtained pitch (8) was measured for reflectivity with the result that the highest and lowest values are 12.4%
and 9.0% respectiveLy.
The pitch (8) was melt spun at a spinning temperature of 320C and a take-up speed of 780 m/min. to obtain 12~-diameter pitch fibers. The thus obtained pitch ~ibers were infusibilized~ carbonized and graphitized under the same conditions as in Example 1 to obtain carbon fibers havirlg a 10-~ diameter, a tensile strength oE 220 Ky/mm2 and a tensile modulus of 23 Ton~mm2.
Compara-tive Example 3 The pitch (7) as obtained in Example 3 was heat treated at 400C and a reduced pressure of 1 mm~lg for 10 hours to obtain a pitch (9) having a softening point of 299C and a reflectivity of 13.2% at the highest and 9.0 at the lowest.
The thus obtained pitch (9) was attempted to be ~ 14 -~ 3 melt spun at a spinning temperature of 360C and a -take-up velocity of 780 m/min. with the result that the pitch (93 was thermally degraded whereby continuous spinning thereof was impossible.
Claims (10)
1. A process for the production of carbon fibers which comprises using as the starting material a specific pitch having the lowest reflectivity in the range of 8.5-9.3% and the highest reflectivity in the range of 11.8-12.5%.
2. A process according to claim 1, wherein said specific pitch is obtained by heating a starting carbonaceous pitch in an inert gas atmosphere to obtain a liquid pitch, forming the thus obtained liquid pitch to a thin film of not larger than 5 mm in thickness, treating the thus formed thin film at a temperature of 200-350°C
and a reduced pressure of 0.1-10 mmHg for 1-30 minutes and then heat treated at a temperature of 300-450°C under atmospheric pressure for 1-60 minutes.
and a reduced pressure of 0.1-10 mmHg for 1-30 minutes and then heat treated at a temperature of 300-450°C under atmospheric pressure for 1-60 minutes.
3. A process according to claim 2, wherein the starting carbonaceous pitch is a heavy fraction oil boiling at substantially 200-450°C obtained as a by-product at the time of steam cracking at 700-1200°C of petroleum comprising at least one member selected from naphtha, kerosene and light oil to produce olefins including ethylene and propylene.
4. A process according to claim 2, wherein the starting pitch is a heavy fraction oil boiling at substantially 200-450°C obtained as a by-product at the time of fluidized catalytic cracking of petroleum comprising at least one member selected from kerosene, light oil and atmospheric pressure bottom oils, at a temperature of 450-550°C and a pressure of atmospheric to 20 Kg/cm2?G in the presence of natural or synthetic silica?alumina catalyst or zeolite catalyst.
5. A process according to claim 2, wherein the starting pitch is a pitch obtained by incorporating 100 parts by volume of a heavy fraction oil boiling at substantially 200-450°C obtained as a by-product at the time of steam cracking at 700-1200°C of petroleum comprising at least one member selected from naphtha, kerosene and light oil to produce olefins including ethylene and propylene, with 10-200 parts by volume of aromatic hydrocarbons of 2-3 rings having their nuclei at least partly hydrogenated to form a mixed oil and then heat treating the thus formed mixed oil at a temperature of 380-480°C and a pressure of 2-50 Kg/cm?G.
6. A process according to claim 2, wherein the starting pitch is a pitch obtained by incorporating 100 parts by volume of a heavy fraction oil boiling at substantially 200-450°C obtained as a by-product at the time of fluidized catalytic cracking of petroleum comprising at least one member selected from kerosene, light oil and atmospheric pressure bottom oils, at a temperature of 450-550°C and a pressure of atmospheric to 20 Kg/cm2?G in the presence of natural or synthetic silica?alumina catalyst or zeolite catalyst, with 10-200 parts by volume of aromatic hydrocarbons of 2-3 rings having their nuclei at least partly hydrogenated to form a mixture and then heat treating the thus formed mixture at a temperature of 380-480°C and a pressure of 2-50 Kg/cm2?G.
7. A process according to claim 2, wherein the starting pitch is a pitch obtained by heat treating said heavy fraction (1) at a temperature of 400-500°C under a hydrogen pressure of 20-350 Kg/cm2?G.
8. A process according to claim 2, wherein the starting pitch is a pitch obtained by heat treating at a temperature of 400-500°C under a hydrogen pressure of 20-350 Kg/cm2?G a heavy fraction oil boiling at substantially 200-450°C obtained as a by-product at the time of fluidized catalytic cracking of petroleum comprising at least one member selected from kerosene, light oil and atmospheric pressure bottom oils, at a temperature of 450-550°C and a pressure of atmospheric to 20 Kg/cm2?G in the presence of natural or synthetic silica?alumina catalyst or zeolite catalyst.
9. A process according to claim 2, wherein the starting pitch is a pitch obtained by (A) incorporating 100 parts by volume of (1) a heavy fraction oil boiling at substantially 200-450°C obtained as a by-product at the time of steam cracking at 700-1200°C of petroleum comprising at least one member selected from naphtha, kerosene and light oil to produce olefins including ethylene and propylene, with 10-200 parts by volume of (2) a hydrogenated oil obtained by contacting with hydrogen in the presence of a hydrogenating catalyst a fraction (i) boiling at 160-400°C produced at the time of steam cracking of petroleum and/or a fraction (ii) boiling between 160-400°C
produced at the time of heat treating at 330-480°C a heavy fraction oil boiling at not lower than 200°C obtained at the time of steam cracking of petroleum, to hydrogenated 10-70% of aromatic nuclei of the aromatic hydrocarbons contained in aromatic nuclei of the aromatic hydrocarbons contained in the fractions (i) and (ii) thereby to obtain a mixture of the oils (1) and (2) and then (B) heat treating the thus obtained mixture at a temperature of 380-480°C
under a pressure of 2-50 Kg/cm2?G thereby obtaining the pitch.
produced at the time of heat treating at 330-480°C a heavy fraction oil boiling at not lower than 200°C obtained at the time of steam cracking of petroleum, to hydrogenated 10-70% of aromatic nuclei of the aromatic hydrocarbons contained in aromatic nuclei of the aromatic hydrocarbons contained in the fractions (i) and (ii) thereby to obtain a mixture of the oils (1) and (2) and then (B) heat treating the thus obtained mixture at a temperature of 380-480°C
under a pressure of 2-50 Kg/cm2?G thereby obtaining the pitch.
10. A process according to claim 2, wherein the starting pitch is a pitch obtained by mixing together a) a heavy fraction oil boiling at substantially 200-450°C
obtained as a by-product at the time of steam cracking at 700-1200°C of petroleum comprising at least one member selected from naphtha, kerosene and light oil to produce olefins including ethylene and propylene, b) a heavy fraction oil boiling at substantially 200-450°C obtained as a by-product at the time of fluidized catalytic cracking of petroleum comprising at least one member selected from kerosene, light oil and atmospheric pressure bottom oils, at a temperature of 450-550°C and a pressure of atmospheric to 20 Kg/cm2?G in the presence of natural or synthetic silica?alumina catalyst or zeolite catalyst and c) a hydrogenated oil obtained by contacting with hydrogen in the presence of a hydrogenating catalyst a fraction (i) boiling at 160-400°C produced at the time of steam cracking of petroleum and/or a fraction (ii) boiling between 160-400°C produced at the time of heat treating at 380-480°C
a heavy fraction oil boiling at not lower than 200°C
obtained at the time of steam cracking of petroleum, to hydrogenate 10-70% of aromatic nuclei of the aromatic hydrocarbons contained in the fractions (i) and (ii), in such amounts that the ratio by weight of said heavy fraction oil a) to said heavy fraction oil b) is 1:0.1-9 and the ratio by weight of the total of said heavy fraction oils a) and b) to said hydrogenated oil c) is 1:0.1-2, to obtain a mixture and then heat treating the thus obtained mixture at a temperature of 380-480°C under a pressure of 2-50 Kg/cm?G.
obtained as a by-product at the time of steam cracking at 700-1200°C of petroleum comprising at least one member selected from naphtha, kerosene and light oil to produce olefins including ethylene and propylene, b) a heavy fraction oil boiling at substantially 200-450°C obtained as a by-product at the time of fluidized catalytic cracking of petroleum comprising at least one member selected from kerosene, light oil and atmospheric pressure bottom oils, at a temperature of 450-550°C and a pressure of atmospheric to 20 Kg/cm2?G in the presence of natural or synthetic silica?alumina catalyst or zeolite catalyst and c) a hydrogenated oil obtained by contacting with hydrogen in the presence of a hydrogenating catalyst a fraction (i) boiling at 160-400°C produced at the time of steam cracking of petroleum and/or a fraction (ii) boiling between 160-400°C produced at the time of heat treating at 380-480°C
a heavy fraction oil boiling at not lower than 200°C
obtained at the time of steam cracking of petroleum, to hydrogenate 10-70% of aromatic nuclei of the aromatic hydrocarbons contained in the fractions (i) and (ii), in such amounts that the ratio by weight of said heavy fraction oil a) to said heavy fraction oil b) is 1:0.1-9 and the ratio by weight of the total of said heavy fraction oils a) and b) to said hydrogenated oil c) is 1:0.1-2, to obtain a mixture and then heat treating the thus obtained mixture at a temperature of 380-480°C under a pressure of 2-50 Kg/cm?G.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP209649/81 | 1981-12-28 | ||
| JP56209649A JPS58115120A (en) | 1981-12-28 | 1981-12-28 | Preparation of pitch type carbon fiber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1189660A true CA1189660A (en) | 1985-07-02 |
Family
ID=16576291
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000418355A Expired CA1189660A (en) | 1981-12-28 | 1982-12-22 | Process for the production of pitch-derived carbon fibers |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4469667A (en) |
| EP (1) | EP0084275B1 (en) |
| JP (1) | JPS58115120A (en) |
| CA (1) | CA1189660A (en) |
| DE (1) | DE3277209D1 (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58115120A (en) * | 1981-12-28 | 1983-07-08 | Nippon Oil Co Ltd | Preparation of pitch type carbon fiber |
| JPS58220805A (en) * | 1982-06-15 | 1983-12-22 | Nippon Oil Co Ltd | Production of precursor pitch for carbon fiber |
| JPS6034619A (en) * | 1983-07-29 | 1985-02-22 | Toa Nenryo Kogyo Kk | Manufacture of carbon fiber and graphite fiber |
| JPS60202189A (en) * | 1984-03-26 | 1985-10-12 | Idemitsu Kosan Co Ltd | Pitch for carbonaceous material and its preparation |
| US4628001A (en) * | 1984-06-20 | 1986-12-09 | Teijin Limited | Pitch-based carbon or graphite fiber and process for preparation thereof |
| US5316654A (en) * | 1985-09-13 | 1994-05-31 | Berkebile Donald C | Processes for the manufacture of enriched pitches and carbon fibers |
| US4759839A (en) * | 1985-10-08 | 1988-07-26 | Ube Industries, Ltd. | Process for producing pitch useful as raw material for carbon fibers |
| JPS6285031A (en) * | 1985-10-09 | 1987-04-18 | Toray Ind Inc | Melt-spinning of pitch |
| JPS62256887A (en) * | 1986-04-30 | 1987-11-09 | Nippon Oil Co Ltd | Production of raw pitch for carbon fiber |
| JPS62276021A (en) * | 1986-05-23 | 1987-11-30 | Nitto Boseki Co Ltd | Production of carbon fiber |
| US4832820A (en) * | 1986-06-09 | 1989-05-23 | Conoco Inc. | Pressure settling of mesophase |
| DE3829986A1 (en) * | 1988-09-03 | 1990-03-15 | Enka Ag | Process for increasing the mesophase content in pitch |
| DE58900814D1 (en) * | 1988-09-03 | 1992-03-19 | Akzo Faser Ag | METHOD FOR INCREASING THE MESOPHASE CONTENT IN PECH. |
| US5061413A (en) * | 1989-02-23 | 1991-10-29 | Nippon Oil Company, Limited | Process for producing pitch-based carbon fibers |
| US5238672A (en) * | 1989-06-20 | 1993-08-24 | Ashland Oil, Inc. | Mesophase pitches, carbon fiber precursors, and carbonized fibers |
| US6350590B1 (en) | 1997-10-30 | 2002-02-26 | C.B.F. Leti, S.A. | Tolerogenic fragments of natural allergens |
Family Cites Families (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2894904A (en) * | 1956-08-28 | 1959-07-14 | Standard Oil Co | Rapid method for the isolation of petrolenes from asphalt |
| GB850880A (en) * | 1957-10-16 | 1960-10-12 | Gelsenkirchener Bergwerks Ag | Process and apparatus for the continuous production of pitch |
| CA1019919A (en) * | 1972-03-30 | 1977-11-01 | Leonard S. Singer | High modulus, high strength carbon fibers produced from mesophase pitch |
| US3976729A (en) * | 1973-12-11 | 1976-08-24 | Union Carbide Corporation | Process for producing carbon fibers from mesophase pitch |
| JPS5360927A (en) * | 1976-11-12 | 1978-05-31 | Nippon Oil Co Ltd | Continuous method of manufacturing petroleum pitch |
| FR2392143A1 (en) * | 1977-05-25 | 1978-12-22 | British Petroleum Co | PROCESS FOR MANUFACTURING CARBON OR GRAPHITE FIBERS FROM NATURAL ORGANIC MATERIAL FIBERS BY USE OF HYPERFREQUENCES |
| FR2392144A1 (en) * | 1977-05-25 | 1978-12-22 | British Petroleum Co | PROCESS FOR MANUFACTURING CARBON AND GRAPHITE FIBERS FROM OIL BRAIS |
| JPS6057478B2 (en) * | 1978-06-28 | 1985-12-14 | 呉羽化学工業株式会社 | Manufacturing method of carbon fiber pitcher |
| US4271006A (en) * | 1980-04-23 | 1981-06-02 | Exxon Research And Engineering Company | Process for production of carbon artifact precursor |
| JPS57168989A (en) * | 1981-04-13 | 1982-10-18 | Nippon Oil Co Ltd | Raw pitch for carbon fiber |
| JPS57179287A (en) * | 1981-04-27 | 1982-11-04 | Nippon Oil Co Ltd | Raw material pitch for carbon fiber |
| JPS57168990A (en) * | 1981-04-13 | 1982-10-18 | Nippon Oil Co Ltd | Raw pitch for carbon fiber |
| JPS57168987A (en) * | 1981-04-13 | 1982-10-18 | Nippon Oil Co Ltd | Raw pitch for carbon fiber |
| US4391788A (en) * | 1981-04-13 | 1983-07-05 | Nippon Oil Co., Ltd. | Starting pitches for carbon fibers |
| JPS57170990A (en) * | 1981-04-14 | 1982-10-21 | Nippon Oil Co Ltd | Raw material pitch for carbon fiber |
| US4397830A (en) * | 1981-04-13 | 1983-08-09 | Nippon Oil Co., Ltd. | Starting pitches for carbon fibers |
| JPS57168988A (en) * | 1981-04-13 | 1982-10-18 | Nippon Oil Co Ltd | Raw pitch for carbon fiber |
| JPS57179285A (en) * | 1981-04-27 | 1982-11-04 | Nippon Oil Co Ltd | Raw material pitch for carbon fiber |
| JPS57179286A (en) * | 1981-04-27 | 1982-11-04 | Nippon Oil Co Ltd | Raw material pitch for carbon fiber |
| JPS5876523A (en) * | 1981-10-29 | 1983-05-09 | Nippon Oil Co Ltd | Preparation of pitch carbon fiber |
| US4497789A (en) * | 1981-12-14 | 1985-02-05 | Ashland Oil, Inc. | Process for the manufacture of carbon fibers |
| JPS58115120A (en) * | 1981-12-28 | 1983-07-08 | Nippon Oil Co Ltd | Preparation of pitch type carbon fiber |
-
1981
- 1981-12-28 JP JP56209649A patent/JPS58115120A/en active Granted
-
1982
- 1982-12-21 US US06/451,939 patent/US4469667A/en not_active Expired - Lifetime
- 1982-12-22 DE DE8282307053T patent/DE3277209D1/en not_active Expired
- 1982-12-22 CA CA000418355A patent/CA1189660A/en not_active Expired
- 1982-12-22 EP EP82307053A patent/EP0084275B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6356325B2 (en) | 1988-11-08 |
| EP0084275A2 (en) | 1983-07-27 |
| JPS58115120A (en) | 1983-07-08 |
| EP0084275A3 (en) | 1985-06-26 |
| US4469667A (en) | 1984-09-04 |
| DE3277209D1 (en) | 1987-10-15 |
| EP0084275B1 (en) | 1987-09-09 |
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